QuestionQUESTION: hello! I saw a post with a similar-seeming problem of the battery draining completely after approx. 3 weeks of non-use. my garage man thinks he has traced this to the fuel pump relay fuse in the ABS fuse box under the bonnet on the passenger-side. we changed that fuse earlier because the car, while having power, would turn on all lights, make pump noises and would crank (I believe that is the term!), but would not start. the garage man checked the fuel pump and ok'ed it, and now I wonder if these two problems are perhaps related? we are in France, and he is not used to Saabs, so I would appreciate any help in pointing him in the right direction! as of yesterday, the car, after not wanting to start at all in the evening the day before (motor cranking, but no 'explosion' noises, no attempt to start), started after much encouragement during the day (temperature important? the car was not starting before in the morning), but, when stopped, would only start again with difficulty. the car had new spark plugs and fuel filter put in four months ago when it had its general servicing.
thank you for any help you can give!
ANSWER: Tamar "Yakirah":
Fuel pumps often fail by not working at voltages below 10-11 volts. This condition occurs during cranking when a heavy electrical load is placed on the battery, thus lowering the voltage.I still believe the fuel pump is the likely problem.
To verify,I recommend the following test:
Bypass the fuel pump relay with the engine OFF by performing the following:
1. Remove fuses 27 and 30
2. Connect a jumper wire between the outboard (fender) side of fuse 30 and the inboard (engine) side of fuse 27
You should hear the fuel pump operating.
Then try to start the engine; if it starts and runs normally, the fuel pump is at fault. If still not, then a further check of the fuel delivery system, in particular the fuel injectors, is required. Also, have you ruled out the electrical ignition system as the problem? Is there any spark going to the spark plugs?
Feel free to respond with your findings and/or any other questions you may have.
Jerry
---------- FOLLOW-UP ----------
QUESTION: dear Jerry,
thank you for your reply - I will have my mechanic try that with the fuses to see whether we can rule out or focus on the fuel pump.
can you think of any reason though why the pump relay fuse would be draining the battery when the car is parked and left to its own devices?
Tamar.
AnswerTamar:
I cannot think of a logical reason for the "battery drain" roblem, except if the relay developed an electrical short somewhere. Did you replace the relay yet and re-test for electrical leakage?
Jerry
